Periodic motion mechanism



Oct. 6, 1942;

c. c. KINKER PERIODIC MOTION MECHANISM Filed Aug. 2, 1940 4 Sheets-Sheetl INVENTOR f @M- 4, a, wwxm OCt. 6, c c KINKER PERIODIC MOTION MECHANISMFiled Aug. 2, 1940 4 Sheets-Sheet 2 INVENTOR 0% 1942- c. c. KINKERPERIODIC MOTION MECHANISM Filed Aug. 2, 1940 4 Sheets-Sheet 4 INVENTOR gVIII/ Patented Oct. 6, 1942 UNITED STATES PATENT OFFICE 2,298,215PERIODIC MOTION MECHANISM Clarence C. Kinker, Montreal, Quebec, CanadaApplication August 2, 1940, Serial No. 349,626

8 Claims. (01. 7444) This invention relates broadly to machines such asglassware-forming machines and particularly to the operating mechanismsof such machines. I

Glassware-forming machines exemplify one type of apparatus in which itis desirable to produce periodic motion and at the same time control themotion throughout the entire period of movement. 7

In glassware-forming apparatus, such as is ordinarily termedglass-forming machinery, it is 10 well established procedure to advancethe moldcarrying table or tables by periodic movements of equal lengthand of equal time duration so that each mold of the table is moved fromstation to station and is brought to rest at each station.

that the movement of the table actuatesat least some of the operatingmechanisms carried by it. For this reason, it is highly desirable tocontrol the periodic movements of the table so that it is bothaccelerated from a stop to maximum speed and decelerated from maximumspeed to a stop without appreciable shock to the various rnechanismsinvolved. It will, of course, .be understood that power will be savedand the efiective life of the operating, as well as the operated,mechanisms will be increased if the periodic movement can beaccomplished without appreciable shock.

One of the objects of the present invention is,

therefore, to produce a driving mechanism for an element such as themold-carrying table of a forming machine, which will'eifectively andefiiciently impart periodic movement to the -element without subjectingthe various moving parts to undue wear and tear.

A further object is to produce an operating 40 mechanism for impartingperiodic motion to a driven element, which occasions an effectiveutilization of-the power employed, and maintains substantially efiectivecontrol of the driven element throughout the entire cycle of itsoperation.

A further object is to produce a driven mecha nism for the mold-carryingtable of a glassforming machine which imparts periodic movement to suchtable under conditions such as to substantially continuously control thesame and to prevent back lash of the moving parts involved.

A further object is to produce a driving mechanism for a periodic movingdevice, such as the mold-carrying table of a glassware-forming machine,which is such as to produce periodic movement similar to that producedby a Geneva drive but which minimizes wear on the moving parts.

A further object is to produce a driving mech-- anism which approximatesthe results accomplished by a so-called Geneva drive, but is such thatthe imparted movement may be substantially controlled, as to the degreeof acceleration or deceleration, throughout all parts of the movementcycle.

These and other objects, which will be made apparent throughout thefurther description of my invention, are accomplished by means ofapparatus illustrated in the drawings, in which Figure 1 is a iragmentaland more or less diagrammatic view of a two-table glass-forming .machinein which each table is provided with a are carried by and employed toimpart motion to' a driven element such as one of the tables illustratedin Figure 1.

Figures 4 to 9, inclusive, showsuccessive positions of the part of thedriving mechanism illustrated in Figure 3 and with Figure 3 illustrate acomplete operating cycle of that mechanism.

Figure 10 is a fragmental view diagrammatically illustrating a differentform of .driving mechanism and also diagrammatically illustrating anarrangement of tables wherein two tables, such as the tables of Figure1, are geared together and both are driven by a single drivingmechanism.

Figures 11 to 17, inclusive, illustrate successive positions of theportion of the driving mechanism illustrated in Figure 10 and withFigure 10 illustrate a complete cycle of that mechanism.

Figure 18 is a fragmental sectional view along the line A--A of Figure13; and

Figure 19 is a fragmental plan view of apparatus such as is shown inFigure 18, but in which more structural details are illustrated.

In Figures 1 and 2, I havediagrammatically illustrated two rotatabletables, such as the moldcarrying tables of a glass article-formingmachine, and I have diagrammatically illustrated in association witheach such table a separate driving mechanism embodying my invention.

2 Each driving mechanism consists essentially of a composite cam mountedfor rotation on a standard 20 which is supported in a suitable pedestaland is driven, i. e., rotated, by means of a worm 2| and a worm wheel,not shown but carried by and rigidly secured to the standard 20.

As shown in Figure 2, the worm 2| is mounted on a shaft 22 which isdriven by a motor 23 and is provided with an automatic, safety, clutchmechanism 24 for connecting it to and disconnecting it from the sourceof power when an over-load is encountered. I have illustrated anextension shaft 22 for the driving mechanism of one of the tables andhave shown it as coupled to the shaft 22. The extension shaft carries aworm 2lwhich drives the associated device through a worm wheel (notshown).

The composite cam which constitutes an important part of each drivingmechanism illustrated in Figures 1 and 2, consists of a heartshaped cam25 which forms a support for a cam 26 and also a cam 21. As illustrated,the cam 26 approximates the shape of a conventional shield or of adistorted crescent. The cam 21 is offset from the cam 25 and the camfaces 21a and 21b are approximately parallel with'the adjacent face ofthe cam 25 and, as will be pointed out hereinafter, cooperates with thatcam in imparting movement to cam rollers.

Each composite cam imparts periodic movement to a rotatably mountedtable 28 and this is accomplished by two series of cam rollers carriedby the table. As illustrated, the cam rollers of the A series arerotatably mounted on depending lugs or brackets 29 carried by or formedon the table 28. This series is arranged to contact with the lowermostcams, viz., the earns 25 and 21, and they are positioned for thispurpose. The cam rollers of the B series are also mounted on dependinglugs or brackets formed on or carried by each table 26, but these lugsor brackets are such that the cam rollers carried thereby clear the cams25 and 21 and are only capable of engaging the cam 26. As shown inFigures 1 and 2, each cam roller of the B series is associated with oneof a cam roller of the A series and the association is such that theaxes of the two rollers define a radius of. the associated table 28, i.e., define a line which extends from the center of rotation C of thetable 28.

For illustrative purposes, each table 28 is shown mounted on a column 30in such a way that the column forms a combination pedestal and amounting column for the table. The rotation of the table is around theaxis of the pedestal or column 30. The structural details of the tableand of its mounting mechanism play no part in the present invention,except insofar as the table is a rotatable table. For this reason I havenot endeavored to disclose full structural details of either table.

In Figure 3 I have indicated by arrow that the composite cam rotates ina clockwise direction around its center of rotation X. The arrows thereemployed in connection with lines radiating from the table center C alsodisclose that the table is rotated in a clockwise direction by theassociated composite cam. Figure 3 is shown in association with a circlestruck from the center of rotation X of the composite cam and subdividedinto arcs for the purpose of co-relating the separate cam positionsillustrated in Figures 3 to 9 with the illustration of Figure 3.

The positions of the cams shown in Figure 1 correspond substantially tothe position of the cam shown in Figure 3, with relation to the camrollers of the table 28 there illustrated. I refer particularly to thecomposite cams 25, 26, 21 of the left-hand portion of Figure 1 because Ihave there designated the associated cam rollers as A, A' and A, B, Band B for the purpose of illustrating the relationship between the camrollers and the composite cam as the table is advanced in its periodicmovement, by the rotation of the cam.

In Figure 1, and consequently in Figure 3 of the drawings, I haveillustrated a relationship between the composite cam and the associatedcam rollers A, B, A and B which exists at the end of a period duringwhich the table is locked or held stationary by the cooperative actionof the composite cam and the cam rollers. This view (Figure 3) fullyillustrates the complete fulfillment of one object of the invention inthat it discloses the cam rollers A and A in engagement with opposedlobes of the cam 25, and the cam rollers B and B in engagement with theopposed lobes of the cam 26 and under conditions such that the table isunder the joint control of both cams 25 and 26 and the four designatedcam rollers. .It will be apparent that a relationship of cams androllers, as here illustrated, positively prevents the driven elementfrom over-running the driving element and, consequently, positivelyprevents back-lash on the part of the driven element, viz., the table28.

For convenience of description, I here note that the composite cam 25,26, 21 is adapted to be continuously rotated at a uniform angularvelocity; that during this rotation the associated driven element, i.e., the mold-carrying table 28, is alternately advanced and locked in astationary position by the cooperative action of the composite cam andthe cam rollers and that the periodic locking of the table in fixedpositions results from the fact that opposed portions of the faces ofboth cams 25 and 26 are so constructed that they follow the arcs ofcircles struck from the center of rotation X of the composite cam andconsequently impart neither an impelling nor a retarding force to thecam rollers contacting therewith. I refer to these circular portions ofthe cam faces as "sections of perfect radius" in order to distinguishthem from other portions of the cam faces which impart eitheran'impelling or a retarding force to the contacting cam roller.

In Figures 3-9, inclusive, I have disclosed a dotted line yy whichpasses through the center of rotation C of the table and also the centerof rotation X of the composite cam. I employ this line 3111 as a datumline for indicating the an-' gular advance of the table which isaccomplished by themovement of the composite cam to the differentpositions illustrated by Figures 3 to 9, inclusive. I also employ adotted line cz on each of the Figures 4 to 9 for the purpose ofdesignating the angular advance of the table and the angle zcy in eachsuch figure designates that advance.

Figure 4 illustrates the relative positions of the composite cam and thetable after the cam is turned through the arc G of Figure 3. During thismovement of the composite cam, all of the cam rollers A, B, A, B moveoflf the perfect radius sections of the cams 25 and 26 and the rollers Aand B cooperate in starting the rotation of the table and also inaccelerating its speed of rotation after it starts to move.

As indicated in Figure 3, the cam roller B moves oil the crescent-shapedcam 26 almost immediately after the composite cam starts its movementthrough the arc G. As a result, the cam roller A assumes the entireburden of checking a tendency on the'part of the table to over-run thedriving device (composite cam) or, in other words, the function ofpreventing back-lash is imposed wholly upon the roller A and the portionof the face of the cam 25 with which it contacts. It should here benoted that the cam roller B is so positioned that it only contacts withthe crescent-shaped cam 25 and it, therefore, ceases to perform anyfunction in connection with the table 28 until it again contacts thatcam.

Figure 4 discloses that the cam roller A is just about to leave thepoint of the heart-shaped cam 25 and that, therefore, further rotationof the composite cam, for example, as through the are H, and to theposition shown in Figure 5, renders the roller A ineifective incontrolling the movement of the table, until it again contacts thecomposite cam.

The lines yy and 2c of Figure 4 disclose that the table is advancedthrough the angle zcy by the rotation of the composite cam through thearc G and the corresponding lines of Figure 5 disclose the angularadvance of zcy by the rotation of the composite cam through the arc G+Hof Figure 3. Figure 5 also discloses that during this movement of thecam, the cam roller A has contacted with the cam face 21a of the cam 21while maintaining its contact with the heart-- shaped cam 25. Underthese conditions, it performs the double function of imparting impellingforce to the associated table 28 and of also preventing back-lash on thepart of the table.

In Figure 5 the cam roller B is about towmove out of contact with thecrescent-shaped cam 25, whereas the cam roller B has just moved intocontact with the inner cam face of that cam. It will, therefore, beunderstood that as the composite cam turns through the are I of Figure 3and moves from the position indicated in Figure 5 to that of Figure 6,the cam rollers A'B will assume the entire function of impelling thetable, whereas the cooperative action between the cam roller A and thecam face 21a will prevent back-lash on the part of the driven element,i. e., the table 28. The above statement should be modified to theextent of noting that as the cam roller A enters the indented or socketportion of the heart-shaped cam 25, it rides off the cam face 21a butstill performs the function of an impelling roller and a back-lashpreventing roller, since it can only move with the cam 25 through theinfinitely short are wherein the cam roller B neither imparts movementto nor checks the movement of the table 28.

Figure 7 illustrates the position of the composite cam after it isturned through the arc G+H+I+J. During this movement, the table has beenadvanced to the angular position disclosed by the angle zcy of Figure 7.As the composite cam moves through the arc J, the

cam roller A cooperates with the heart-shaped cam 25 in impelling thetable and the crescentshaped cam 26 cooperates with the roller B inpreventing back-lash on the part of the table. It should also be notedthat during this movement of the composite cam, the cam face 21b of thecam 21 cooperates with the roller A in preventing back-lash and that acam roller 13 moves into contact with the outer face of thecrescent-shaped cam.

As the composite cam moves through the arc K of Figure 3 or from theposition shown in Figure 7 to that shown in Figure 8, the table isadvanced to the angular position indicated by the angle zcu of Figure 8.During this movement, the cooperation between the heart-shaped cam 25and the roller A continues to advance the table 28 and the cam roller Bperforms the function of preventing back-lash. Figure 8 discloses thatthe cam roller B has moved out of contact with the inner face of thecrescentshaped cam 26 and is moving to a position where it is engaged bythe outer face of that cam. The figure also discloses that the camroller A is Just moving into contact with the tip of the heart-shapedcam 25.

As the composite cam turns from the position shown in Figure 8 to thatshown in Figure 9, it moves through the are L of Figure 3. During thismovement, the roller A continues to engage an active impelling face ofthe cam 25 and to impel the table 28. The cam roller B is in contactwith an impelling face of the crescentshaped cam 25 and consequentlycooperates with the cam A in impelling the table. Back-lash is preventedby the cooperative action of the cam rollers A and B which respectivelyengage the cams 25 and 2B.

As the composite cam turns to the position illustrated in Figure 9, i.e., through the arcs G+H+I+J+K+L, the table has been advanced throughthe angle zcy of Figure 9 which is a full 60. That is to say, the tablehas been advanced from one stop position to the next and consequentlyfurther movement of the composite cam, in completing one cycle of itsoperation, merely contributes to a locking of the driven element (table28) in a stationary position.

As the composite cam turns from the position illustrated in Figure 9 tothat illustrated in Figure 3, i. e., through the arc M of Figure 3, thecam rollers A and A move onto perfect radius sections of theheart-shaped cam 25 and the cam rollers B and B move onto correspondingsections of the crescent-shaped cam 25, with the result that the movingcam forms a lock for the table and holds the table in a definiteposition until the cam arrives at, and proceeds beyond a positioncorresponding to that illustrated in Figure 3. In connection with thislocking of the table, it should be noted that the composite cam isengaged by four cam rollers throughout its entire locking travel. Thisinsures holding the table definitely in position and independently ofsuch surface defects as may exist at some portion of a cam or camroller.

The apparatus illustrated is designed to accomplishthe rotation of asix-station table, i. e., a table which is periodically advanced throughangles of 60 and moved to an index position at the end of each suchadvance. In glass-forming machinery, this would be termed a six-moldtable. In such machines, the table must be accurately positioned at theend of each such advance movement and for this reason it is notonlydesirable, but necessary to prevent back-lash and thus assure that thetable comes to a stop at a definite point in its travel. The advancingand stopping of the table at the different stations is termed indexing,because of the accuracy of positioning required, and the mechanism hereillustrated and described is of such character that each complete cycleof the driving mechanism,

i. e., of the composite cam, will not only move the table the sameangular amount, but will also lock the table in-an accuratelyestablished position, thus insuring that all parts of the glass-formingor other devices carried by the table are moved to proper positions withrelation to cooperating mechanisms adjacent to but not carried by thetable. That is to say, each cycle of the driving mechanism will advancethe driven mechanism an amount exactly equal to every other advancemovement and will also look the driven mechanism in a definitepredetermined position immediately upon arrival at the predeterminedposition.

Another feature of the present invention is that apparatus embodying itmay be so designed as to produce a desired rate of acceleration .anddeceleration of the driven mechanism. While it is highly desirable tostart and stop a driven element without shock, it is also desirable toaccomplish the complete operating cycle of the driven element in asshort a time as possible. With this in mind, the importance of producinga predetermined rate of acceleration and deceleration will be apparent.This feature of the invention is accomplished, in the illustratedembodiments, by providing the driving mechanism with two impelling andback-lash-preventing devices.

In the embodiment described and illustrated in Figures 1 to 9,inclusive, one such device may be said to include the heart-shaped cam25 and the associated cam 21, together with the cam rollers of theseries A. The other such device may be said to include thecrescent-shaped cam 26 and the cam rollers of the series B whichcooperate with it.

A consideration of the driving mechanism heretofore described willdisclose that the so-called separate devices operate both jointly andsingly as impelling and back-lash-preventing devices. That is to say,the cam 25 and its associated parts sometimes cooperate with the cam 28and its associated parts, both in impelling the driven element and inpreventing back-lash on the part of that element. During a portion ofthe cycle it (the cam 25) may cooperate with the cam 25, and associatedparts, in impelling the driven element; or it may operate independentlyof all other cams in impelling the driven element; or, for some portionof the angle, it and a cooperating cam roller, may constitute the solemeans for preventing back-lash; or it may operate in connection with thecam 26 in preventing back-lash. Thus it is apparent that the driving andbacklash preventing functions are shifted back and forth between the twodevices although the shift from one device to the other is usuallypreceded by a period of joint or cooperative operation.

In Figures to 19, inclusive, I have illustrated a further embodiment ofmy invention wherein the structural details are such as to make itclearly apparent that the driving mechanism is made up of two separate,but at the same time, cooperating devices, each of which is capable ofimpelling or propelling the driven element and also of preventingback-lash on the part of that element. As illustrated in Figure 10, themodified form of driving mechanism consists essentially of a combinedcam assembly and driving pinion. The cam assembly is similar in somerespects to the heart-shaped cam 25 and the associated cam part 21heretofore described and it cooperates with a series of rollers,corresponding to the series of rollers A, in impelling, stopping andpositively aces ms locking the driven element in predeterminedpositions.

For convenience of description, it is noted that each of said cams 25,24 and 21 may be designated as a motion-controlling means; that the camrollers A, A and A, et'c.,'may be designated as one series of contactmembers; and that the cam rollers B, B and B, etc., may be designated asa second series of contact members. It is also noted that the contactmembers A, A and A. etc., of the first-mentioned series are adapted toengage and cooperate with two of the motioncontrolling cams, viz., thecams 25 and 21, whereas the contact members of the second series (B, B'B, etc.) are only capable of engaging and cooperating with one suchmotion-controlling means, viz., the cam 25.

In Figure 10, I have shown two table gears 44 and 4| which are gearedtogether so that a single driving mechanism may be employed in drivingboth of them. A ring gear 42 is shown secured to the spokes of the gear40 in such relationship that the two gears 40 and 42 are coaxiallylocated. It might be here noted that the driving mechanism illustratedin Figures 10-19, like the driving mechanism previously described, is

arranged to advance the driven element (gear 40) through an arc of 60and then stop it and lock it in position. That is to say, the table isindexed every 60 of its rotation. For this reason, the cam assemblyforming a part of the driving mechanism cooperates with six cam rollersD which are spaced 60 apart circumferentially of the gear 45 and which,for convenience of illustration, are shown mounted on the spokes of thatgear in such relationship that they are held in place by the samedevices that secure the ring gear 42 to the gear 40.

As clearly shown in Figure 18, the driving mechanism includes a standard20 which corresponds to the standard 20 of the so-called composite cam.This standard carries a pinion segment 43 which is rigidly securedthereto and is adapted to mesh with and drive the gear ring 42. Thecenter of segment 43 is coincident with the axis of rotation of thestandard 200 and, as is clearly disclosed by the drawings, the segmentis adapted to rotate with that standard and with the cam assemblyconstituting a part of the driving mechanism. This cam assembly issecured to the standard but is located below the pinion segment 43. Itconsists of a combination of two cams 44 and 45 which are illustrated asintegrally formed and rigidly securedvto the standard 25a. The cam 44 issubstantially heart-shaped and the cam 45 is similar in shape topreviously described cam 21 and cooperates with the cam 44 in much thesame way that the cam 21 cooperates with the cam 2-5. The two cams areso located that they provide a cam-way 45 capable of receiving a camroller D and of such dimensions, with relation to the roller, that thetwo cams cooperate-in controlling the position of the roller andconsequently of the driven gear 44.

It will be apparent from the further description that the cams 44 and 45in some ways correspond in function to the cams 25 and 21 heretoforedescribed and that the gear element 43 is somewhat similar in functionto the cam 25 and that each of these elements 41, 44 and 45 may,therefore, be designated as a motion-controlling means. It might also benoted that the cam rollers D, D and D, etc., correspond in structure andfunction to the first series of contact members heretofore described, inthat they enmakes it apparent that the angular advance of gageand'cooperate with both of the motioncontrolling means 44 and 45,whereas such of the individual gear teeth of the gear 42 as intermeshwith the teeth of the segmental gear 43 may be designated as the secondseries of contact members in that they engage and cooperate with but onemotion-controlling means, via, the segmental gear 43.

In Figure 10, the driving mechanism isshown in a relationship with thedriven element 46 such that movement of the driving mechanism in acounter-clockwise direction will start to move the,

driven element (gear 46) from the I stationary position in which it hasbeen locked by the cooperative relationship of the cam 44 and the camrollers DI and D2. The driving mechanism and consequently the segmentgear 43 and the cams 44 and 45 rotate continuously and at asubstantially uniform angular velocity ina counterclockwise directionwith the result that, with the parts as shown in Figure 10, .the rollerD2 isjust moving into the cam-way 46 formed between opposed active facesof the cams 44 and 45. Under such conditions, the acting face of the cam44 functions to impel the roller D2, and consequently the driven element(gear 40), in a clockwise direction while the cooperating face of thecam 45 confines the roller D2 in such a way as to prevent back-lash onthe part of the driven element.

It might here be noted that the relationship of the parts is such thatthe driving mechanism rotates through 315 to advance the table gear 40through an arc of 60 in the operation of indexing the associated tableor tables. The remaining 45' of angular travel of the driving mecha nismis employed in looking the table gear 40 in an indexed position after ithas been brought to rest.

In Figure 11 I have shown the driving mechanism after it has advancedthrough 50 of travel beyond the position illustrated in Figure 10. Theroller D2 has entered the cam-track 46 and has been moved in a clockwisedirection, with relation to the center of rotation of the gear 40. Theroller DI has been moved out of contact with the cam 44 and ceases tofunction as a motion control device until it again moves into contactwith that cam. It will also be noted that the first tooth of the pinionsegment 43 is about to go into mesh with the gear ring 42 and thusimpose a driving function on the gear segment and ring.

The cams 44 and 45, disclosed by the drawings, are so proportioned thattheir opposed but cooperating faces are adapted to uniformly acceleratethe driven gear 40 at the rate of 135-79- 11-13-15-17-19 units per 5 ofangular cam travel of the driving mechanism. Thus it is apparent thatthe cam-way 46 is of such form as to accelerate the driven element froma stop to full speed in 50 of angular motion. In addition, thecooperative relation between the' cams 44 and 45 (cam-way 46) and thecontacting cam roller D, is such that the pitch circle of the ring gear42 is moving at the same peripheral speed as the pitch circle of thepinion segment 43 after the driving mechanism has accelerated the drivengear 40 from a stop to its maximum speed of rotation, i. e., after thedriving mechanism has advanced from a position such as illustrated inFigure to a position such as illustrated in Figure 11.

A- reference to the drawings will disclose that the pinion segment 43 isin mesh with the gear the gear 40 is uniform for all positions of thedriving mechanism illustrated in those figures, 1. e., during the entireperiod the pinion segment is in mesh with the gear ring. It will also beapparent that during this period the pinion segment drives or cooperatesin driving the driven gear 40.

In Figure 12 the roller D2 is still in engagement with the opposed andactive faces of the cam-track 46, thus making it apparent that thefunctioning of the cam assembly overlaps that of the intermeshing gearelements 42 and 43 in both driving the gear 40 and in preventingbackring 42 in Figures 11 to 15, inclusive, and this lash. It will,however, be apparent that there is no necessity for this doublefunctioning of the driving-mechanism during the period that the motionimparted to the driven element is wellestablished' as a uniform motion,consequently the faces of the cam-way 46 may be relieved, as shown bythe dotted lines 41-41 of Figure 12, thus imposing the entire functionof impelling and preventing back-lash upon the intermeshing gear ring 42and pinion segment 43.

In Figure 13 I have shown the relative position of the drivingmechanism, the gear ring 42 and the cam rollers DI and D2 when thedriving mechanism has advanced through 157 /2 of that portion of itscycle during which it imparts movement to the driven gear 40. That is tosay, the positions of the parts illustrated in Figurel3 are thoseassumed when the driving mechanism has advanced half-way through its 60indexing movement. It will be apparent that in this position of thedriving mechanism the pinion segment 43 is assuming the entire functionof driving and controlling the positioning of the driven element if, assuggested, the active faces of the cam-way 46 are relieved asillustrated by the dotted lines 41 of Figure 12. I

In Figure 14 I have shown the relative positions of the parts after thedriving mechanism has.

turned through 215 of its motion-imparting travel. A cam roller D3(carried by the driven gear 46) is approaching the driving mechanism andthe gear D2, within the cam-track 46, is approaching that portion of thetrack wherein the active faces of the cams 44 and 45 again cooperatewith the gear segment 43 in controlling the movement of the drivenelement. That is to say, the cam-way 46 cooperates in driving the drivenelement and also in preventing back-lash.

Figure 15 discloses the relative position of the parts as the last toothof the pinion segment 43 moves out of mesh with the gear ring 42 andthus imposes the entire function of controlling the movement of the gear40 on the cooperating cams 44 and 45 and the cam roller D then engagedby those cams. It will also be apparent that during the next 50 ofangular travel of the driving mechanism, that mechanism must function todecelerate the driven gear 40 as a preliminary to bringing it to a stop.Comparison of the opposite ends of the cam-way 46 discloses that thedeceleration takes place at the same rate as the acceleration.

In Figure 16 I have shown the relative positions of the parts at the endof the decelerating travel of the driving mechanism, 1. e., at theposition where the driven'element (table gear 40) is initially broughtto rest. It should be noted, in connection with this figure of thedrawings, that the cam roller D3 is now contacting with the active faceof the cam 44 and that it, therefore, cooperates with the roller D2 inlooking the gear 40 in the index position. It will be understood fromthe former description of the composite cam of Figures 3-9 that both camrollers D2 and D3 are contacting with and consequently moving along aperfect radius section of the cam 44.

In Figure 17 I have shown the relationship of parts when the drivingmechanism has moved through half that portion of its travel during whichthe driven element is rigidly locked in position by the cooperativerelation between the cam 44 and two of the cam-engaging rollers Dcarried by the driven element. As the driving mechanism continues itsrotation in a counterclockwise direction from the position shown inFigure 17 to that shown in Figure 10, the driven element 40 continues tobe held against movement and upon reaching the position shown in Figurethe driving mechanism has completed a cycle of its operation. Duringeach such cycle, the driving mechanism accelerates the driven elementfrom a stop to a uniform speed, continues the rotation of that elementat the uniform speed throughout a substantial arc of its travel and thendecelerates the driven element to a stop whereupon it (the drivingmechanism) locks the driven element against further motion and continuesto function as a lock while rotating throughout the remaining are (45)of its angular travel.

It will also be apparent that during each such cycle the function ofpropelling the driven element and of preventing back-lash shifts fromthe cam assembly (cams M and 45) to the gear elements 42 and 43 and thenfrom those elements back to the cam assembly and all while the drivingmechanism is rotating at a substantially uniform angular velocity.

By employing a cam assembly as an active portion of the drivingmechanism, I accomplish a flexibility of control over the drivenmechanism which would be at least difficult to accomplish with any othertype of mechanical motion. That is to say, I can predetermine the rateof acceleration to be employed in accelerating the driven element from astop to maximum velocity and I can also predetermine the rate ofdeceleration to be employed in bringing the driven element to a stop ateach of the stop positions. This is accomplished by properlyproportioning the active faces of the cam assembly (cam-way 46). In thisway I can also predetermine the relationship between the period duringwhich the driven element is held stationary, the period during which itis accelerated, the period during which it is propelled at asubstantially uniform velocity and the period during which it isdecelerated to a stop. In addition, all this can be predetermined interms of angular velocity of the driving mechanism so that the desiredrelationship of these periods can be maintained during the operation ofthe apparatus and independently of the speed of rotation of the drivingmechanism.

In addition to the above, by employing a cam assembly similar to thoseillustrated, I am able to positively lock the driven mechanism in theindex positions as soon as it arrives at those positions. Then, too, theuse of a cam assembly and the associated cam-engaging parts makes itpossible to more effectively prevent back-dash on the part of the drivenelement than with other forms of motion-producing apparatus. For thisreason, it is highly desirable to employ a cam assembly for propellingthe driven element during the periods of its acceleration anddeceleration,

i. e., during those periods when there is a pronounced tendency on thepart of the driven element to either lag behind or over-ride the drivingmechanism.

In this connection, it may be noted that I prefer a combination of camassembly and gear drive wherein the cam assembly continues to functioneven after the gearing (uniform-velocity drive) mechanism has beenoperating a sufficient time interval to establish the uniform motion ofthe driven element. That is to say, if the cam assembly is renderedineffective throughout the period that the gearing mechanism iseffective, then I prefer an operative relationship as disclosed anddescribed in connection with Figure 12. It, however, will be understoodthat the cam 44 may be cut away as disclosed by the dotted lines SI-Blof Figure 11 and that the active face of thecam 45 can becorrespondingly relieved without rendering the combination cam assemblyand gearing mechanism ineffective as a driving mechanism for the tablegear 40.

Figure 19 is a view corresponding to Figure 10, except that it is on alarger scale, omits the table gear 4| and includes a fragmental view ofa transmission mechanism a, similar in function and arrangement to thetransmission mechanism 49 of Figure 1. Figure 19 also includes a more orlessdiagrammatic representation of a drive shaft 22a, associated parts,a worm 2Ia driven by the shaft, and a worm gear 50 driven by the worm 2la. The worm gear 50 is shown in dotted lines in Figure 19 and as anintegral part of or carried by the standard 20a.

Figure 18 is a sectional view of the apparatus shown in Figure 10 withthe section taken along the line XVIII-XVIII, as shown in Figure 13.That is to say, the section is taken so as to illustrate therelationship of table gear 40, ring gear 42, pinion segment 43, camassembly 44 and I5 and one of the cam rollers D at a point in the cycleof operation 'where the driven element has been advanced half-waybetween two index points. As there shown, the mounting lug and boltemployed for the purpose of securing the cam roller D2 in place may alsobe employed as a part of the means employed in securing the ring gear 42to the table gear 40.

While I have illustrated but two embodiments of my invention, it will beapparent that various changes, additions and omissions may be made inthe apparatus illustrated without departing from the spirit and scope ofthe invention as defined by the appended claims.

Having thus described my invention, what I claim is:

1. A periodic motion-producing apparatus including a rotatably mounteddriving element, a rotatably mounted driven element, means to rotatesaid driving element at a substantially constant angular velocity, acomposite cam assembly and gear assembly actuated by said drivingelement for alternately imparting motion from said driving element tosaid driven element, said cam assembly including two separatemotion-controlling cams mounted on and movable with said driving elementand a. series of contact members mounted on said driven element andspaced circumferentially thereof and so arranged with relation toperipheral faces of said cams that one such face of said cam assembly isengaged by two contact members to hold said driven member againstangular motion in either direction and so that two of such surfaces areengaged by one such member while said cam assembly is accelerating anddecelerating said driven element, said gear assembly including gearteeth carried on and movable with said driving element and gear teethcarried on and movable with said driven member which periodically moveinto mesh with said first-mentioned gearteeth.

2. A periodic motion-producing apparatus including a rotatably mounteddriving element, a rotatably mounted driven element, means for rotatingsaid driving element at a substantially constant angular velocity, acomposite driving mechanism actuated by said driving element forsuccessively holding said driven element stationary,-then acceleratingsaid driven element from rest to its maximum angular velocity, thendriving said driven element at a uniform angular velocity and thendecelerating said driven element from such maximum uniform angularvelocity to rest, comprising gear assembly carried in part by saiddriving element and in part by said driven element for impartinguniform, rotary motion to said driven element and a cam assemblycomprising two motion-controlling cams carried by said driving elementand a series of cam contact members mounted on said driven element,spaced circumferentially thereof and so arranged that one such member issimultaneously controlled by two of said cams and then one of said camsis simultaneously engaged by two contact members while said, drivingelement is rotating at a substantially constant angular velocity andsaid gear assembly is ineffective in imparting motion to said drivenmember.

3. A periodic motion-producing apparatus including a rotatably mounteddriving element, means for driving said element at a substantiallyconstant angular velocity, a rotatably mounted driven element and acomposite driving mechanism actuated by said driving element forsuccessively holding said driven element stationary, accelerating saiddriven element from rest to a uniform angular velocity, deceleratingsaid driven element from such uniform angular velocity to rest,comprising three cooperating motioncontrolling cams carried by androtatable with said driving element, two series of cam contact membersmounted on said driven element with the members of each seriescircumferentially spaced with relation to said driven element and soarranged with relation to said cams that the contact members of oneseries engage but one of said cams, whereas the contact members of theother series engage and cooperate with each of the two remaining camsand in which the relationship between said contact members and such camsis such that the driven element is always controlled by the cooperativeeffect of opposed cam surfaces.

4. A periodic motion-producing apparatus including a rotatably mounteddriving element, means for rotating said element at a substantiallyconstant angular velocity, a rotatably mounted driven element and acomposite driving mechanism actuated by said driving element forsuccessively holding said driven element stationary, accelerating saiddriven element from rest to its maximum angular velocity, anddecelerating said driven element from such maximum uniform angularvelocity to rest, comprising three separate motion-controlling meanscarried by and rotating with said driving element, two series of contactmembers mounted on said driven element with the members of each seriesspaced circumferentially thereof, and so arranged that the members ofone series contact with but one of said motion-controlling means,whereas the members of the other series engage each of the two remainingmeans, during the acceleration 5. A periodic motion-producing apparatusincluding a rotatably mounted driving element,

means for rotating said element at a substantially constant rate, amovably mounted driven element and a composite driving assembly actuatedby said driving element for successively holding said driven elementstationary, then gradually accel erating said driven element from restto a uniformtvelocity, then driving said driven element at a uniformvelocity and then decelerating said driven element from such uniformvelocity to rest, comprising a gear assembly carried in part by saiddriving element and in part by said driven element for driving saiddriven element at a uniform velocity and a cam assembly comprising twomotion controlling cams carried by and movable with said driving elementand a series of spaced cam contact members mounted on said drivenelement and so arranged that two such members simultaneously contact acam to hold said driven member stationary and one such member issimultaneously engaged by two cams while said driving member is movingsaid driven member at a varying rate of speed.

6. A periodic motion-imparting apparatus including a rotatably mounteddriving element, means for rotating said element at a substantiallyconstant angular velocity. a rotatably mounted driven element, a gearassembly and a composite cam assembly for alternately. imparting motionfrom said driving element to said driven element, said gear assemblycomprising intermeshing series of gear teeth, one such series beingmount ed on and rotating with said driving element and the other suchseries being mounted on and rotating with said driven element, said camassembly comprising a substantially heart-shaped cam mounted on andmovable with said driving memher, a substantially wing-shaped cammounted on and moving with said driving member and forming with saidheart-shaped cam a camway, and a series of cam contact members mountedon said driven member and circumferentially spaced with relation theretoand so arranged that two such members contact said heart-shaped cam tohold said driven member stationary during the rotation of such cam andone such member moves through said camway while accelerating anddecelerating said driven element.

7. A periodic motion-producing apparatus including a rotatably mounteddriving element, a rotatably mounted driven element, mechanisms forrotating said driving element at substantially constant angularvelocity, a composite driving mechanism actuated by said driving elementfor successively holding said driven element stationary, thenaccelerating it from rest at its maximum angular velocity, then drivingit unii'ormly at such maximum angular velocity and then decelerating itfrom such maximum angular velocity to rest, comprising motion-impartingmeans carried in part by said driving element and in part by said drivenelement for imparting a uniform angular velocity to said driven elementand a cam assembly comprising two motion-controlling cams mounted on andmovable with said driving element and a series of cam contact membersmounted on and movable with said driven element, spacedcircumferentially thereof and so arranged that each such member isperiodically simultaneously controlled by both said cams and then one ofsaid cams is periodically simultaneously engaged by two of said contactmembers while said driving element is rotating at a substantiallyconstant angular velocity and said motion-imparting means is ineflectivein driving said driven element.

8. A periodic motion-producing apparatus including a rotatably mounteddriving element, mechanisms for rotating said element at a substantiallyconstant velocity, a rotatably mounted driven element and a compositedriving mechanism actuated by said driving element for successivelyholding said driven element stationary,

accelerating it from rest to its maximum angular velocity, anddecelerating it from such maximum angular velocity to rest, comprisingmotion-imparting means carried in part by said driving element and inpart by said driven element for p..- riodically driving said drivenelement, and two separate motion-controlling cams mounted on androtating with said driving element and a series 01' contact membersmounted on said driven element spaced circumferentially thereof and soarranged that each such member is periodically controlled by both saidcams and then one of said cams is simultaneously engaged by two suchmembers while said driving element is rotating at substantially constantangular velocity and said motion-imparting means is ineflective indriving said driven element.

CLARENCE C. KINKER.

